Method and apparatus for joint replacement arthroplasty

The present invention is a continuation application of U.S. patent application Ser. No. 17/866,639, filed on Jul. 18, 2022, which was a continuation application of U.S. patent application Ser. No. 16/082,539, filed on Sep. 6, 2018, which was a national phase application of PCT/IL2017/050285, filed on Mar. 8, 2017, claiming priority benefit from U.S. patent application Ser. No. 15/064,673, filed on Mar. 9, 2016 (now U.S. Pat. No. 9,717,599), all of which are incorporated herein by reference in their entirety.

The present invention relates to medical implants. More specifically, the present invention relates to a method and an apparatus for joint replacement arthroplasty.

A human joint is an interface that bridges two or more bones, and permits a variety of movements between the two or more bones at the joint. A wrist joint, or a knee joint, for example, include bones that intercommunicate in a common synovial cavity. Wrist articulations work together to allow for a wide range of motions in the joint. Most of the wrist motion, for example, occurs in the radiocarpal joint (RCJ) and the distal radioulnar joint (DRUJ). Most of the knee motion occurs in the tibiofemoral joint.

Different joint pathologies may occur in the bones or joints resulting from conditions such as osteoarthritis, or from traumas, such as bone fractures, for example. A patient, or subject, with these joint pathologies may experience severe pain during movements of the joint ranging to severe disabilities due to limitations in joint movements.

When severe joint pathologies occur, therapeutic methods such as the use of medications may not alleviate the pain and movement limitations in the joints of the patient. Partial or full joint replacement arthroplasty may be the best course of treatment for the patient.

There is thus provided, in accordance with some embodiments of the present invention, a radiocarpal joint replacement apparatus for implantation in a wrist of a subject, including a radial member configured to be affixed to a portion of an end of the radial bone proximal to the wrist including a fixture to be affixed over a longitudinal aspect of the radial bone and a radial resurfacing plate having a substantially concave surface configured to be located at the end of the radial bone, a carpal capitate bone insert configured to be inserted and affixed into the carpal capitate bone, and a bulbous component comprising a first convex head and a second convex head, substantially opposite each other and connected by a neck defining an annular groove between the first convex head and the second convex head, wherein the carpal capitate bone insert is configured to be flexibly coupled to the first convex head of the bulbous component, and wherein the radial resurfacing plate of the radial member with the concave surface is configured to be operably coupled to the second convex head of the bulbous component so as to allow radial freedom of motion of the carpal capitate member with respect to the radial resurfacing plate after the implantation.

Furthermore, in accordance with some embodiments of the present invention, the carpal capitate bone insert includes a dorsal cortical plate and an intraosseous stem, the intraosseous stem inserted into the carpal capitate bone, and the carpal capitate bone insert is affixed to the carpal capitate bone with screws inserted through holes in the dorsal cortical plate and the intraosseous stem.

Furthermore, in accordance with some embodiments of the present invention, the carpal capitate bone insert includes a screw threaded into the carpal capitate bone so as to affix the carpal capitate insert to the carpal capitate bone.

Furthermore, in accordance with some embodiments of the present invention, the carpal capitate bone insert includes petals configured to be inserted into the annular grove so as to flexibly hold the bulbous component to the carpal capitate bone insert.

Furthermore, in accordance with some embodiments of the present invention, the carpal capitate bone insert includes an implant insertion element coated with hydroxylapatite.

Furthermore, in accordance with some embodiments of the present invention, the bulbous component is formed from a material selected from the group consisting of polyethylene, ceramic, and pyrocarbon.

Furthermore, in accordance with some embodiments of the present invention, the radial resurfacing plate is formed from a polished metal surface.

Furthermore, in accordance with some embodiments of the present invention, the fixture is V-shaped.

Furthermore, in accordance with some embodiments of the present invention, the radiocarpal joint replacement apparatus, includes a hook formed on the radial member facing the ulna bone and proximal to the wrist, and an ulnar member configured to be affixed to a portion of an end of the ulna bone proximal to the wrist and opposite to the hook, the ulnar member including a bore configured to receive hook, and retain the hook after implantation, wherein the bore is shaped to allow relative movement between the radial bone and the ulna bone so as to facilitate supination and pronation movement of the wrist of the subject.

Furthermore, in accordance with some embodiments of the present invention, the ulnar member is formed from a receptacle piece and a mounting piece.

Furthermore, in accordance with some embodiments of the present invention, the bore is C-shaped.

There is further provided, in accordance with some embodiments of the present invention, a distal radioulnar joint replacement apparatus for implantation in a wrist of a subject, including a sigmoidal member configured to be affixed onto a portion of an end of the radial bone proximal to the wrist including a lower mounting bracket to be affixed over a longitudinal aspect of the radial bone so as to face the ulna bone, the sigmoidal member including a hook, and an ulnar member configured to be affixed to a portion of an end of the ulna bone proximal to the wrist and opposite to the sigmoidal member, the ulnar member including a bore configured to receive hook, and retain the hook after implantation, wherein the bore is shaped so as to allow relative movement between the radial bone and the ulna bone so as to facilitate supination and pronation movement of the wrist of the subject.

Furthermore, in accordance with some embodiments of the present invention, the sigmoidal member includes a triangular peg implanted into cancellous bone at the end of the radius bone.

Furthermore, in accordance with some embodiments of the present invention, the bore is C-shaped.

Furthermore, in accordance with some embodiments of the present invention, the ulnar member is formed from a receptacle piece and a mounting piece.

Furthermore, in accordance with some embodiments of the present invention, the receptacle piece is formed from a material selected from the group consisting of mobile polyethylene and pyrocarbon, and the mounting piece is formed from a material selected from the group consisting of stainless steel and titanium.

There is further provided, in accordance with some embodiments of the present invention, a radiocarpal joint cartilage replacement apparatus for implantation in a wrist of a subject including a radial member configured to be affixed to a portion of an end of the radial bone proximal to the wrist including a fixture to be affixed over a longitudinal aspect of the radial bone and a radial resurfacing plate having a substantially concave surface configured to be located at the end of the radial bone, and a cartilage replacement member with a first surface and a second surface wherein after implantation, the first surface is configured to be operably coupled to the carpal bones in the wrist and configured to be affixed to the radial member on the second surface.

Furthermore, in accordance with some embodiments of the present invention, the cartilage replacement member is configured to be affixed to the radial member on the second surface by one or more tabs formed on the cartilage replacement member that are respectively inserted and held within one or more holes formed in the radial member.

Furthermore, in accordance with some embodiments of the present invention, the cartilage replacement member is formed from plastic.

Furthermore, in accordance with some embodiments of the present invention, the fixture is V-shaped.

There is further provided, in accordance with some embodiments of the present invention, a joint replacement apparatus for implantation into an articulation between a first and a second bone in a subject, the apparatus includes a first member and a second member. The first member is configured to be affixed to an end of the first bone proximal to the articulation between the first bone and the second bone. The first member includes one or more first member fixtures to be affixed externally to cortical bone tissue along a longitudinal aspect of the first bone, and a first resurfacing plate configured to be located at the end of the first bone. The second member is configured to be affixed to an end of a second bone proximal to the articulation. The second member may include one or more second member fixtures configured to be affixed externally to cortical bone tissue along a longitudinal aspect of the second bone, and a second resurfacing plate configured to be located at the end of the second bone, where each of the first and the second resurfacing plates are shaped, to fit and to move together, so as to facilitate anatomical movements of the articulation.

Furthermore, in accordance with some embodiments of the present invention, the articulation includes a proximal interphalangeal joint, the first bone includes a middle phalange bone, and the second bone includes a proximal phalange bone.

Furthermore, in accordance with some embodiments of the present invention, the articulation includes a tibiofemoral joint, the first bone includes a femur bone, and the second bone includes a tibia bone.

Furthermore, in accordance with some embodiments of the present invention, the articulation comprises a radiocarpal joint (RCJ), the first bone comprises a carpal capitate bone, the first member fixture comprises a cortical plate, the first resurfacing plate comprises a convex head of a bulbous component, the second bone comprises a radius bone, the second member fixture comprises a radial fixture, and the second resurfacing plate comprises a radial articular resurfacing plate.

Furthermore, in accordance with some embodiments of the present invention, the one or more first member fixtures and the one or more are second member fixtures are configured to be externally affixed to cortical bone tissue along a longitudinal aspect of the respective first and second bone by screwing screws into screw holes in each of the fixtures.

Furthermore, in accordance with some embodiments of the present invention, wherein the first resurfacing plate and the second resurfacing plate are configured to be affixed to the end of the respective first and second bone proximal to the articulation by screwing screws through screw holes respectively in the one or more first member fixtures and the one or more second member fixtures into peg holes in pegs attached respectively into the first or the second resurfacing plates.

In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those of ordinary skill in the art that the invention may be practiced without these specific details. In other instances, well-known methods, procedures, components, modules, units and/or circuits have not been described in detail so as not to obscure the invention.

Although embodiments of the invention are not limited in this regard, discussions utilizing terms such as, for example, “processing,” “computing,” “calculating,” “determining.” “establishing”. “analyzing”. “checking”, or the like, may refer to operation(s) and/or process(es) of a computer, a computing platform, a computing system, or other electronic computing device, that manipulates and/or transforms data represented as physical (e.g., electronic) quantities within the computer's registers and/or memories into other data similarly represented as physical quantities within the computer's registers and/or memories or other information non-transitory storage medium (e.g., a memory) that may store instructions to perform operations and/or processes. Although embodiments of the invention are not limited in this regard, the terms “plurality” and “a plurality” as used herein may include, for example. “multiple” or “two or more”. The terms “plurality” or “a plurality” may be used throughout the specification to describe two or more components, devices, elements, units, parameters, or the like. Unless explicitly stated, the method embodiments described herein are not constrained to a particular order or sequence. Additionally, some of the described method embodiments or elements thereof can occur or be performed simultaneously, at the same point in time, or concurrently. Unless otherwise indicated, use of the conjunction “or” as used herein is to be understood as inclusive (any or all of the stated options).

Previously, different wrist implant topologies involved the resection of portions of the radius and/or ulna bones and affixing portions of the implant components, such as pegs, within the soft intramedullary canal. Such soft tissue stabilizing techniques of the implant components in the soft medullary tissue have been shown to loosen over time and ultimately fail, which requires additional surgery to fix and re-stabilize the implants. Moreover, in some implant topologies, the implant components may be bolted across multiple carpal bones to fix the multiple carpal bones in place severely limiting wrist movements. Some implants may bond portions of the radius to the ulna particularly in the case after large resections of those bones. These implant topologies severely limit the motion in the multiple wrist joints and may cause early loosening of the implant.

Described herein are some embodiments of a method and apparatus for wrist arthroplasty including radiocarpal joint (RCJ) and distal radioulnar joint (DRUJ) replacements. A method and apparatus for renewing the articular surface of the distal radius with a cartilage replacement can be used to repair damage, for example, from intra-articular fractures of the distal radius (e.g., from sport injuries) according to some embodiments of the present invention is also taught herein without the need to replace the entire joint (e.g., hemi-arthroplasty). Implant solutions according to some embodiments of the present invention overcome many of the implant failure and joint mobility problems seen in previous wrist implants and prostheses.

Wrist implants according to some embodiments of the present invention further account for minimal bone resection, preservation of the mobility of the radiocarpal, intercarpal and carpometacarpal joints, and a reduction of shear, bending and frictional forces in the implant components so as to prevent a loosening of the implant. Wrist implant topologies according to some embodiments of the present invention do not apply a classic ball and socket approach to the joint, but apply methods of joint articular surface reconstruction to the complex joint surfaces. Implant technologies according to some embodiments of the present invention include wrist implant topologies which combine radiocarpal joint (RCJ) replacement with the option of DRUJ resurfacing replacement and stabilization within the same implant.

Implant topologies according to some embodiments of the present invention utilize a plate fixation method whereby the implant components are plate-like and use screws to affix the plate components to the hard outer cortical bone layers for better implant stability. There is minimal bone resection with minimal placement of the implant components within the soft issue of the medullary cavity to stabilize the implant. Plate-like components used in some embodiments of the present invention employ a closed frame construction, such as the Y-plate affixed to the radius used in the RCJ implant as will described later, so as to achieve maximum contact and mechanical stability of the implant with prevention of implant failure. Surgical techniques employed according to some embodiments of the present invention for implanting the wrist replacements are simple and easy.

schematically illustrates a dorsal view of a handwith a first embodiment of a radiocarpal joint (RCJ) replacement, in accordance with some embodiments of the present invention. Handincludes metacarpal bones, and the carpal bones, or carpus, including carpal trapezoid bone, carpal trapezium bone, carpal capitate bone, carpal hamate bone, and carpals triquetral/pisiform bones.

To implant the RCJ replacement shown inin the wrist of hand, the carpal lunate bone is removed from a regionfrom hand. A carpal scaphoid boneis surgically cut along a cut planeand cartilage is removed from the RCJ. Radius boneand ulna boneare shown in.

A radial memberof the RCJ replacement includes holesthrough which fasteners, typically screws, are to be inserted and threaded to allow affixing, attaching, or locking radial memberto a portion of an end of radius boneproximal to the wrist. In contrast to the problems associated with soft tissue mounting of implants, radial memberis typically affixed to the cortex of radius bone(e.g., cortical bone tissue of the radius bone) so as to provide a solid mechanical support for the RCJ replacement.

A carpal capitate memberincludes a carpal capitate bone insertand a bulbous component. Carpal bone insertof the RCJ replacement is configured to be inserted and affixed only to carpal capitate boneof the wrist, but not to other carpal bones, allowing greater maneuverability of the wrist, as a result. Carpal capitate bone insertis coupled to bulbous component, which includes a convex headsubstantially opposite to carpal capitate bone insert.

schematically illustrates an exploded view of radiocarpal joint (RCJ) replacement, in accordance with some embodiments of the present invention. Radial memberof the radiocarpal joint (RCJ) replacement includes a radial fixtureto be affixed over a longitudinal aspect of the radial bone. Radial fixturemay have various forms, designed to match and provide good anchorage and coupling with the radius bone when attached to it. For example, radial fixturemay be V-shaped designed to present two joined bars that are to be affixed laterally onto radial bone.

Radial memberfurther includes a radial articular resurfacing platehaving a substantially smooth concave surface that is to be located at the end of the radial bone proximal to the wrist for supporting the radial memberwhen in-situ. The wrist includes the carpal bones and multiple joints that intercommunicate in a common synovial cavity. “Proximal” to the wrist refers, in the context of the present application, to the side of radial bonenearest the carpal bones. This portion of the radial bone is referred to, in the context of the present application, as the distal radius. Radial articular resurfacing plateis attached substantially perpendicular to V-shaped radial fixtureas shown in.

Carpal capitate bone insertincludes a dorsal surface cortical plateand a central intraosseous stem. A bulbous componentis configured to be flexibly coupled to carpal capitate bone insertand located substantially opposite to carpal capitate bone insert. Bulbous componentincludes a convex headhaving a convex surface (e.g., the articular resurfacing plate of carpal capitate member).

Dorsal surface cortical plateis a fixture of carpal capitate memberwhich is externally affixed to the cortical bone tissue of carpal capitate bone. Dorsal cortical plateis maneuvered, during the implantation procedure, to be positioned on the dorsal cortical position of carpal capitate boneand stemis inserted into the central intraosseous position of the carpal capitate bone. Four screw holesfor four screwsare located on both stemand plateof insert. Four screwstraverse carpal capitate bonein the dorsal to palmar direction so as to affix plateto carpal capitate boneand central intraosseous stem; however, any number screws may be used.

The head of stemincludes several petals, in this example, four petals. Two petalsare generally oriented in the dorsal-volar direction and two petalsare generally oriented in the radioulnar direction. The petals are flexibly configured to snap-in, or connect to a neck, so as to hold bulbous componentto carpal capitate bone insert.

Radial articular resurfacing plateof radial memberwith the concave surface is configured to be operably coupled to the convex surface of convex headof bulbous componentof carpal capitate memberso as to allow radial freedom of motion of bulbous componentof carpal capitate memberwith respect to radial articular resurfacing plateafter implantation. Note that the term “operably coupled” in the context of wrist arthroplasty is defined herein to mean that in coupling, bonding, connecting or otherwise holding together the two components forming the wrist joint replacement, implant, or prostheses, with two articulating surfaces, the motion of the two articulating surfaces are identical, or most closely replicate, the same motions found in equivalent in vivo joint articulating surfaces (e.g., anatomical movements of the RCJ articulation). Stated differently by way of example, the movements, or motions, of the RCJ replacement after implantation would most closely replicate the same movements, or motions, found equivalently in a normal (healthy) radiocarpal joint in the wrist.

Radial fixture(the dorsal plate), includes holesthrough which fasteners, typically screws, are used for plate fixation of radial memberto the radial bone cortex. This technique for assembling the RCJ replacement is referred to, in the context of the present application, as dorsal radius fracture fixation. In some embodiments, holeshave threading for screwsto be fixed to radial member. One or more holeson the central region of the “V” pass are oval shaped. Screwing screwinto a chosen side of oval holeapplies a longitudinal stress to fixturein the direction of the chosen side so as to allow an additional degree of freedom for placing and fastening radial fixtureto radius bone. Although a V-shaped radial fixture is described, aimed at providing good mechanical stability, other shapes may be considered, too. The V-shape is not in any way limiting the embodiments of the present invention to that shape. Other shapes for the radial fixture may be used with varying number of screws and respective screw holes in any geometric orientation.

Radial fixture(dorsal plate) is also connected to radial articular resurfacing plate. Two triangular pegsthat are formed in the bottom side of radial articular resurfacing plateare designed to be pressed against and penetrate into the end of the radius bone as shown in, for enhanced stability. Triangular pegsalso include holes. Screwsmay be screwed through obliquely threaded screw holesformed in radial fixture(e.g., dorsal plate). Screw holesare not on the same lateral position along both side of fixtureso as to compensate for the shapes of radial boneand the end of radial bone(e.g., the radial articular surface). Screwspass through radius boneto threaded screw holesandat an oblique angle of about 43 degrees with the bottom surface of radial articular resurfacing plateopposite radius bone. Fastening screwsare used for affixing radial membervia pegsof the radiocarpal joint (RCJ) replacement to radial bone, which forms a mechanically stable pyramid-like closed frame, enhancing self-support.

schematically illustrates a first side view of radial member, in accordance with some embodiments of the present invention.